Aviut from the side of the Kli is lack of its fulfilment, Hissaron, hunger, or appetite. On the other hand, Aviut that comes from the side of the Light is the realization of the Creator’s importance, the revelation of His greatness.
The Light descends and expands your Kli, making the One who Gives Light appear higher in your eyes. It’s best to advance precisely by virtue of this Aviut.
Suppose someone invites me to their house and wants to treat me to tea and cookies. I don’t see anything special about this. However, if I were to suddenly find out that this person is very important and influential, the visit would acquire a totally different meaning for me! The Prime Minister of Great Britain, Benjamin Disraeli wrote in his memoirs that the Queen once invited him to her palace for tea. Prior to that he had conversed with her many times, but this “cup of tea” meant a lot more to him.
In other words, a person is always impressed by whom he receives from, rather than what he receives. By praising the Creator, you expand your spiritual vessels. You come closer to Him by admitting His importance and greatness. The illumination that comes from Him increases in your eyes and this creates additional Kelim inside you.
From the lesson on Shamati on 11/19/10
A Screen In The Black Cosmos Of Desire